The Default Mode Network as Core Consciousness

As you read this, in the background—or perhaps the foreground—is the wandering mind. This basal activity may be best represented in current neuroscience by the Default Mode Network (DMN). The DMN is key for autobiographical narrative and sense of self (Menon, 2023), as well as our bodily self, or "embodied cognition."

The DMN is a marvel of nature: a set of brain regions with differing cytoarchitectural structure, partly insulated from sensory input, partly receiving it. The DMN has an aspect of itself that is cut off from the rest of the environment, which does not receive sensory input from the rest of the brain (Paquola et al., 2025). Intriguing, and discussed more below, the posterior DMN contains a model of the activity of the brain itself, an internal simulation of the self within the self, which must be critical for our capacity to reflect on ourselves—a metaphorical mental hall of mirrors¹.

But how do we make sense of this complexity to understand how the brain "produces" the mind, and how this creates a you, a me, or a we? A recent paper in Current Opinion in Behavioral Sciences by Luppi, Lyu and Stamatakis (2025) provides an integrated view of the DMN as the hypothetical "core of consciousness." They note evidence for the DMN in humans, primates, and even mice, speaking to its foundational role in the mammalian brain.

As one of the networks in the "triple network model," the DMN sits below the Central Executive Network (CEN, also known as the Frontoparietal Network), which manages cognitive control and many intentional activities, with higher-order aspects related to self-awareness and social processes. DMN and CEN connect through the Salience Network (SN), which shifts focus between networks, influencing whether we're in a focused, goal-directed state or otherwise. We can influence how the SN operates to stay focused or let our attention wander—though sometimes we're distracted when we don't wish to be.

Five Key Operations of the DMN

1. DMN as nexus of anatomical and functional convergence and divergence

The DMN is both divergent—differing in many ways, including between individuals—and convergent—maintaining stable patterns over time. The DMN differs most in humans compared to other animals, with the greatest genetic differences and biggest variations in form and connectivity. Importantly, the DMN function is more independent of gene expression than other brain areas.

Convergently, the DMN is a central hub for information from across the brain. The rear DMN reverberates with distant brain activity, perhaps running an internal model of the whole system in miniature. Time runs long for the DMN, binding experiences: "Cognitively, this contextualisation manifests as the DMN facilitating the convergence of information from internal representations, goals, and memories to inform ongoing cognition."

2. Both DMN convergence and divergence are compromised in perturbations of consciousness

Understanding DMN function when the brain is injured could lead to clinical breakthroughs. Stimulating the DMN might help people "wake up" from coma. Early neuromodulation work (Lord et al., 2024) using transcranial focused ultrasound stimulation (TFUS) shows we can stimulate the posterior cingulate cortex with sound beams, reducing functional connectivity and creating changes in subjective self-experience akin to meditative states, such as altered sense of time and ego, and changes in remembering. Deep brain stimulation via implanted electrodes would allow for additional targeting and maintaining of various ongoing stimulation protocols.

3. DMN as the brain's global workspace to integrate environment and self

The DMN is a candidate for the mind's global workspace. According to global workspace theory, this refers to a functional hub facilitating communication and integration across specialized processing modules. This balance of divergence and convergence creates dynamic equilibrium, or flowing balance ("fließgleichgewicht," von Bertalanffy, 1968). There's constant tension between expansion and compression—metaphorically called "tensegrity."² When we self-reflect, we likely perceive our own DMN activities, as the DMN appears to run a real-time simulation of the mind within itself. This self-interaction is almost certainly critical to subjective experience and the recursion giving rise to our beautiful, sometimes vexing, complexity.

4. Collapse of the functional hierarchy under loss of consciousness and psychedelics

During anesthesia, disorders of consciousness like delirium, and with psychedelics, DMN activity alters—specifically connectivity between sensory regions and DMN. The individual "brain fingerprint" becomes less distinct, restored upon returning to ordinary consciousness. Functional connectivity between DMN and FPN reduces, diminishing sense of self. Some therapeutic potential of psychedelics links to dissolution and reconstitution of self. Research remains unclear whether this effect is core to therapeutic benefit for conditions like depression, as animal studies find LSD-like molecules modified to eliminate the "trip" still reduce depression-like behaviors (Tuck et al., 2025).

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5. Therapeutic potential to rebalance DMN function and restore consciousness

Understanding how DMN functional connectivity disruptions can be measured and corrected with therapeutics to restore "euconnectivity"³ and optimize outcomes is compelling for further research. While medications and therapy affect DMN function, we're entering an era of more targeted neuromodulation. Functional brain imaging and mapping technologies will likely provide personalized treatment—analyzing fMRI to develop personalized TMS protocols. This has been done with PTSD by stimulating surface structures with deeper connections (Siddiqi et al., 2024). TFUS can reach deeper regions—stimulating the posterior cingulate cortex changes DMN connectivity, increasing mindfulness and altering sense of self.

The Future of the DMN

We're at an intriguing moment as brain models increasingly converge with models of mind and subjective experience. As one of the main players in triple network theory, the DMN is portrayed as a hub of core consciousness—a big piece of what makes us uniquely ourselves. Crucially, DMN represents what's happening in the rest of the brain with an internal model, one of the ways the brain self-monitors and regulates. Like visual areas containing a mapping of what the eye sees, the DMN has a map of what the inner eye sees—a map of the brain within the brain.

The DMN is partly isolated from sensory input, suggesting it may comprise a private sense of self. The tension between public and private experience is intrinsic to our understanding of the DMN. From a psychoanalytic perspective, it is tempting to wonder how much of this privateness of the DMN could be related to the dynamic unconscious—the deeper aspects of the psyche which are hidden from us, but which can be made conscious through therapeutic and developmental work.

The almost mystical experience of how experiences appear to come from nowhere—and how self-reflection updates self-related functions via growth and development—are elucidated in our understanding of how the DMN works. Far from being quiet, the DMN is noisy, always active, never fully still, a fundamental signal rising from the noise of neuronal complexity. And while the DMN may not be the "source" of consciousness—which according to neuropsychoanalyst and neuropsychologist Mark Solms may lie deeper in the brain's reticular activating system and periaquaductal grey matter⁴, rather than the cerebral cortex—DMN seems to integrate core bottom-up and top-down influences in our basic sense of self as an essentially human middle layer of dynamic organization.

The tension between internal and external, coded into DMN convergent and divergent connectivities, may give rise to, or significantly contribute to, consciousness and self-awareness. Interventions affecting the DMN directly are expected to impact core sense of self, opening therapeutic opportunities particularly with targeted interventions.